If its the LB7 motor they are notorious for injectors going after 100k miles! Other then that the regular front end wear like tie rods, ball joints, pitman and idler arms. It gets the best mpg out of all the duramax motors though. Hope this helps

The '04.5 & '05 LLY had overheating problems under heavy loads. Problem can easily be solved though by adding the mouthpiece from a MD Kodiak/Top-Kick truck. The LB7 injectors had 200,000 mile warranty on them(not sure on time limit) and are a common defect. Other than those issues it's a solid engine. I'd recommend visiting dieselplace.com for more info.Posted via Mobile Device

I just traded in my 02. The injectors were just starting to go bad for the 3rd time. The truck had 140K miles on. I just had the injectors fixed 2 years ago at a cost of $4700. The 200,000 mile injector warreny is good for 7 years from when the truck was built. Don't get a LB7.